| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To achieve a plant control system equipped with a function for protecting a security level so that the security level can be prevented from being changed in any unintended timing. <P>SOLUTION: This plant control system is provided with an engineering device for changing a security status and a controller equipped with a security management means for accepting a security level change request to be downloaded from the engineering device, and for changing a security level by referring to a stored password. This controller is provided with a change permitting means for permitting the security managing means to change the security level. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
